초록 ▼

A vehicular drive system switchable between a continuously-variable and step-variable shifting states, and a control device for controlling the vehicular drive system so as to reduce a shifting shock of an automatic transmission included in the drive system, which takes place due to an overlap contr

A vehicular drive system switchable between a continuously-variable and step-variable shifting states, and a control device for controlling the vehicular drive system so as to reduce a shifting shock of an automatic transmission included in the drive system, which takes place due to an overlap control involving a switching control of the drive system and a shifting control of the automatic transmission. Execution-timing control means 82 is provided to command switching control means 50 and step-variable shifting control means 54 to sequentially execute a switching control by the switching control means to switch transmission mechanism 10 between an electrically established continuously-variable shifting state and a step-variable shifting state, and a shifting control by the step-variable shifting control means to shift an automatic transmission portion 20, even when an overlap control involving the switching control and the shifting control is required, whereby the switching and shifting controls can be rapidly completed. Since the transmission mechanism 10 is not switched during the shifting control of the automatic transmission portion 20, the input speed of the automatic transmission portion 20 will not change due to the switching control, apart from a change of the input speed as a result of the shifting control, making it possible to prevent the complicated shifting control and reduce the consequent shifting shock.

대표청구항 ▼

1. A control device for a vehicular drive system which is arranged to transmit an output of an engine to a drive wheel of a vehicle and which comprises a switchable type transmission mechanism including (i) a power distributing mechanism switchable between a continuously-variable shifting state in w

1. A control device for a vehicular drive system which is arranged to transmit an output of an engine to a drive wheel of a vehicle and which comprises a switchable type transmission mechanism including (i) a power distributing mechanism switchable between a continuously-variable shifting state in which the power distributing mechanism is operable as an electrically controlled continuously variable transmission, and a step-variable shifting state in which the power distributing mechanism is operable as a step-variable transmission, and (ii) an automatic transmission, said control device comprising: a switching controller configured to control said power distributing mechanism selectively in one of said continuously-variable shifting state and said step-variable shifting state, on the basis of a condition of the vehicle;a shifting controller configured to control a shifting operation of said automatic transmission included in the switchable type transmission mechanism, on the basis of the condition of the vehicle; andan execution-timing controller configured to control said switching controller to sequentially execute a switching control of said power distributing mechanism and to control said shifting controller to sequentially execute a shifting control of said automatic transmission, so as to prevent an overlap control involving simultaneous execution of both said switching control and said shifting control, when the switching control of the power distributing mechanism and the shifting control of the automatic transmission are judged to overlap each other. 2. The control device according to claim 1, wherein said execution-timing controller commands said switching controller and said shifting controller such that said switching controller executes said switching control before said shifting controller executes said shifting control. 3. The control device according to claim 1, wherein said execution-timing controller commands said shifting controller and said switching controller such that said shifting controller executes said shifting control before said switching controller executes said switching control. 4. The control device according to claim 1, wherein said execution-timing controller determines one of said switching control by said switching controller and said shifting control by said shifting controller which should be executed before the other of said switching and shifting controls, on the basis of the condition of the vehicle. 5. The control device according to claim 1, wherein said execution-timing controller determines one of said switching control by said switching controller and said shifting control by said shifting controller which should be executed before the other of said switching and shifting controls, on the basis of one the continuously-variable and step-variable shifting states in which said switchable type transmission mechanism is presently placed. 6. The control device according to claim 1, wherein said execution-timing controller determines one of said switching control by said switching controller and said shifting control by said shifting controller which should be executed before the other of said switching and shifting controls, on the basis of one of the continuously-variable and step-variable shifting states to which said switchable type transmission mechanism is to be switched. 7. The control device according to claim 1, wherein said switching controller includes a high-speed-running determining portion configured to determine that the vehicle is in a high-speed running state when an actual value of a running speed of the vehicle is higher than a predetermined upper limit value, said switching controller controlling said switchable type transmission mechanism to said step-variable shifting state when said high-speed-running determining portion has determined that the vehicle is in said high-speed running state. 8. The control device according to claim 1, wherein said switching controller includes a high-output-running determining portion configured to determine that the vehicle is in a high-output running state when a drive-force-related value of the vehicle is higher than a predetermined upper limit value, said switching controller controlling said switchable type transmission mechanism in said step-variable shifting state when said high-output-running determining portion has determined that the vehicle is in said high-output running state. 9. The control device according to claim 1, wherein said switching controller places said switchable type transmission mechanism in one of said continuously-variable and step-variable shifting states, on the basis of an actual value of a running speed of the vehicle and an actual value of a drive-force-related value of the vehicle and according to a stored switching boundary line map including a high-speed-running boundary line and a high-output-running boundary line which are defined by parameters in the form of said running speed of the vehicle and said drive-force-related value. 10. The control device according to claim 1, wherein said switching controller includes electric-path-function diagnosing means for determining whether a function of any one of control components for placing said switchable type transmission mechanism in said continuously-variable shifting state is deteriorated, said switching controller placing said switchable type transmission mechanism in said step-variable shifting state when said electric-path-function diagnosing means has determined that the function of said any one of the control components is deteriorated. 11. The control device according to claim 1, wherein said switchable type transmission mechanism includes an electric motor, a power distributing mechanism operable to distribute the output of said engine to said first electric motor and a power transmitting member, and a second electric motor disposed between said power transmitting member and said drive wheel, said power distributing mechanism having a first element fixed to said engine, a second element fixed to said first electric motor, and a third element fixed to said second electric motor and said power transmitting member, and wherein said power distributing mechanism includes an operating-state switching device operable to switch said switchable type transmission mechanism between said continuously-variable and step-variable shifting states,and said switching controller controls said operating-state switching device to thereby switch said switchable type transmission mechanism between said continuously-variable and step-variable shifting states. 12. The control device according to claim 11, wherein said operating-state switching device includes a coupling device operable to connect any two of said first through third elements to each other, and/or fix said second element to a stationary member, and wherein said switching controller places said switchable type transmission mechanism in said continuously-variable shifting state by releasing said coupling device to thereby permit said first element, said second element and said third element to be rotated relative to each other, and places said switchable type transmission mechanism in said step-variable shifting state by engaging said coupling device to thereby connect at least two of said first element, said second element and said third element to each other or fix said second element to said stationary member. 13. The control device according to claim 12, wherein said power distributing mechanism is a planetary gear set including a carrier functioning as said first element, a sun gear functioning as said second element, and a ring gear functioning as said third element, and wherein said coupling device includes a clutch operable to connect any two of said carrier, sun gear and ring gear to each other, and/or a brake operable to fix said sun gear to said stationary member. 14. The control device according to claim 13, wherein said planetary gear set is of a single-pinion type. 15. The control device according to claim 14, wherein said switching controller controls said coupling device to connect said carrier and said sun gear to each other, to thereby enable said planetary gear set of the single-pinion type to operate as a transmission having a speed ratio of 1, or fix said sun gear to said stationary member, to thereby enable said planetary gear set of the single-pinion type to operate as a speed-increasing transmission having a speed ratio lower than 1. 16. The control device according to claim 11, wherein said automatic transmission is disposed between said power transmitting member and said drive wheel and connected in series to said power distributing mechanism, and said switchable type transmission mechanism has a speed ratio determined by a speed ratio of said automatic transmission. 17. The control device according to claim 16, wherein said switchable type transmission mechanism has an overall speed ratio determined by a speed ratio of the power distributing mechanism and the speed ratio of said automatic transmission. 18. The control device according to claim 16, wherein said automatic transmission is a step-variable automatic transmission which is shifted according to a stored shifting boundary line map.